JP5153623B2 - Method for producing polishing composition - Google Patents

Description

  The present invention relates to a polishing composition for polishing a substrate, and more particularly to a method for producing a polishing composition for polishing a metal portion of a substrate. The present invention also relates to a substrate polishing method and a substrate manufacturing method using the manufactured polishing composition.

Advances in technology in ICs (Integrated Circuits) and LSIs (Large Scale Integrations) have improved their operating speed and integration scale. For example, higher performance of microprocessors and larger capacity of memory chips Has been achieved rapidly. Microfabrication technology greatly contributes to these high performances. One of the fine processing techniques is a chemical mechanical polishing method which is a flattening technique. This chemical mechanical polishing method is used for planarization of interlayer insulating films, metal plugs, and wiring metals in a multilayer wiring process.
Of these, in recent years, an attempt has been made to use copper or a copper alloy as a wiring metal because of a problem of wiring delay. As shown in FIG. 1, as a method of manufacturing a wiring using copper or a copper alloy, a groove is formed in the interlayer insulating film 11 in advance, and if necessary, a barrier film 12 such as tantalum or tantalum nitride is thinned. There is a damascene method of forming and depositing a layer 13 of copper or copper alloy. At this time, since copper or copper alloy is excessively deposited on the upper part of the interlayer insulating film, the wiring 13 ′ is formed by polishing to remove the excess copper or copper alloy while performing planarization.
As a magnetic recording medium, a magnetic storage device (MRAM) has attracted attention. In the MRAM, in order to record information in a specific bit in the element array, a bit write line and a word write line that cross the array vertically and horizontally are provided, and selective writing is performed using only elements located in the intersection region. A method (for example, see JP-A-10-116490) is known. Here, a metal wiring is formed. The metal wiring is composed of a conductor layer made of aluminum or an aluminum alloy, copper or a copper alloy, and a ferromagnetic layer such as nickel-iron (permalloy) so as to surround the conductor layer. If necessary, a barrier film such as tantalum or tantalum nitride is formed thin so as to sandwich the ferromagnetic layer. This metal wiring is formed by the damascene method, but the extra conductor layer, ferromagnetic layer and barrier film are planarized and removed while polishing.
When such wiring is formed, the dishing 14 (FIG. 1) in which the metal portion to be polished is scraped or erosion is generally made as small as possible due to problems such as an increase in wiring resistance and a wiring short circuit. .
On the other hand, as shown in FIG. 2, the cap layer and the antireflection film 15 formed before the formation of the barrier film 12 may be left. In such a case, since the film thickness of the antireflection film or the like is large, when the dishing is small, when the antireflection film is completely removed by barrier polishing, the wiring copper 13 'is raised, causing a wiring short circuit. For this reason, a certain degree of deep dishing is formed at the time of wiring metal polishing, and measures are taken so that the wiring does not rise during barrier polishing. The thickness of such an antireflection film is about several tens of nanometers, and when combined with the barrier film, it is about 20 to 100 nm. This thickness is thin locally in the first layer and thicker globally.
In such a case, it is very advantageous if there is a polishing method in which dishing can be changed by wiring.
Further, when performing the same polishing in many batches, the dishing amount may change every time the polishing batch is passed due to factors other than the polishing composition (for example, deterioration of the polishing pad). If a polishing composition in which the dishing amount is adjusted for each polishing batch can be used so as to cancel out this change, a constant dishing can be obtained regardless of the polishing batch.
However, among metal polishing compositions, there are compositions with large dishing and compositions with small dishing, but no method has been found for easily obtaining a polishing composition with controlled dishing.

The present invention provides a method for producing a polishing composition capable of controlling dishing, a substrate polishing method for planarizing a substrate with the polishing composition, and a method for producing a substrate including the step of planarizing by this method. It is intended to do. Here, “controlling dishing” means that only the dishing amount is adjusted, and other characteristics (for example, polishing rate, etc.) do not change significantly.
As a result of intensive studies on solving the above problems, the present inventors have found that the above problems can be solved by mixing two kinds of polishing compositions (preliminary compositions), and have completed the present invention.
That is, the present invention is shown in the following [1] to [25].
[1] A metal film embedded on a substrate having a recess so as to cover the recess, or a barrier metal film formed on the substrate having a recess and polishing the metal film embedded so as to cover the recess, A method for producing a plurality of types of polishing compositions having different dishing amounts, wherein the plurality of types of polishing compositions are mixed with two types of preliminary compositions (A) and (B) having different compositions. 1 or 2 or more types selected from the group consisting of (a) abrasive grains, (b) oxidizing agents, (c) amino acids, organic acids, and inorganic acids. A composition containing an acid of (d), a surfactant, and using a composition containing (a) abrasive grains and (b) an oxidizer as a preliminary composition (B), giving different dishing amounts A method for producing a seed polishing composition.
[2] The preliminary composition (B) further comprises (c) one or more acids selected from the group consisting of amino acids, organic acids, and inorganic acids, and (d) a surfactant. In (A) and the preliminary composition (B), at least one type of the polishing composition according to [1], wherein at least one concentration of (a), (b), (c), and (d) is different. How to manufacture.
[3] The method for producing a plurality of types of polishing compositions according to the above [2], wherein the concentration of the abrasive grains (a) of the preliminary composition (A) is higher than that of the preliminary composition (B).
[4] The polishing composition according to [2] or [3], wherein the concentration of the oxidizing agent (b) in the preliminary composition (A) is lower than that in the preliminary composition (B). Method.
[5] The concentration of one or more acids (c) selected from the group consisting of amino acids, organic acids, and inorganic acids in the preliminary composition (A) is lower than that in the preliminary composition (B). The method to manufacture the multiple types of polishing composition as described in any one of said [2]-[4].
[6] The plurality of types of [2] to [5], wherein the concentration of the surfactant (d) in the preliminary composition (A) is higher than that in the preliminary composition (B). A method for producing a polishing composition.
[7] One or both of the preliminary compositions (A) and (B) further include an azole group-containing compound having a molecular weight of 300 to 15000 having three or more azole groups in the molecule, [6] A method for producing a plurality of types of polishing compositions according to any one of [6].
[8] Both preliminary compositions (A) and (B) contain the azole group-containing compound, and the concentration of the azole group-containing compound in the preliminary composition (A) is lower than that of the preliminary composition (B). A method for producing a plurality of types of polishing compositions according to the above [7].
[9] Producing a plurality of types of polishing compositions according to any one of [1] to [8], wherein one or both of the preliminary compositions (A) and (B) further contains an anticorrosive agent. how to.
[10] The method for producing a plurality of types of polishing compositions according to [9], wherein the anticorrosive is benzotriazole, tolyltriazole, hydroxybenzotriazole, carboxybenzotriazole, benzimidazole, tetrazole, or quinaldic acid.
[11] Both the preliminary compositions (A) and (B) contain the anticorrosive agent, and the anticorrosive concentration of the preliminary composition (A) is higher than that of the preliminary composition (B) [9] Or the method of manufacturing the multiple types of polishing composition as described in [10].
[12] A plurality of kinds of polishing compositions according to any one of [1] to [11], wherein one or both of the preliminary compositions (A) and (B) further contain an alkali. Method.
[13] The method for producing a plurality of types of polishing compositions according to [12], wherein the alkali is one or more selected from the group consisting of ammonia, ethylenediamine, and propylenediamine.
[14] Both the preliminary compositions (A) and (B) contain the alkali, and the alkali concentration of the preliminary composition (A) is lower than that of the preliminary composition (B). 13] The method for producing a plurality of types of polishing compositions according to [13].
[15] The method for producing a plurality of types of polishing compositions according to any one of [1] to [14], wherein the pH of the produced polishing composition is 5 to 11.
[16] One type wherein the surfactant is selected from the group consisting of an alkyl aromatic sulfonic acid having 8 or more carbon atoms, a phosphoric acid ester having an alkyl group having 8 or more carbon atoms, and a fatty acid having an alkyl group having 8 or more carbon atoms Or the method of manufacturing the multiple types of polishing composition as described in any one of said [1]-[15] which is 2 or more types.
[17] The plurality of polishing compositions according to any one of [1] to [16], wherein the concentration of the abrasive grains (a) with respect to the polishing composition during polishing is 0.01 to 30% by mass. How to manufacture.
[18] The plurality of polishing compositions according to any one of [1] to [16], wherein the concentration of the oxidizing agent (b) with respect to the polishing composition during polishing is 0.01 to 30% by mass. How to manufacture.
[19] The plurality of polishing compositions according to any one of [1] to [16], wherein the concentration of the acid (c) with respect to the polishing composition during polishing is 0.01 to 10% by mass. How to manufacture.
[20] A plurality of polishing compositions according to any one of [1] to [16], wherein the concentration of the surfactant (d) with respect to the polishing composition during polishing is 5% by mass or less. how to.
[21] A polishing composition is produced by the method according to any one of [1] to [20], and the substrate is polished with the polishing composition, whereby the dishing amount of the substrate is adjusted and planarized. A method for polishing a substrate.
[22] The polishing method according to [21], wherein the temperature of the polishing composition is 30 ° C to 50 ° C.
[23] The polishing method according to [21] or [22], wherein the metal film is copper or a copper-containing alloy.
[24] The polishing method according to any one of [21] to [23], wherein the barrier metal film is tantalum or a tantalum alloy.
[25] A method for producing a substrate having a dishing amount in the range of 1 to 300 nm, comprising a step of polishing the substrate by the polishing method according to any one of [21] to [24].
According to the present invention, since dishing can be controlled by polishing with a combination of two kinds of preliminary compositions, a dedicated metal polishing composition when a plurality of planarization steps are included in the manufacturing process of one IC chip. It becomes possible to manufacture a substrate without having to use a plurality of the substrates.
Furthermore, when different types of IC chips are required, the same two types of preliminary compositions can be used for them, and the substrate can be used without changing the metal polishing composition, the polishing pad and the polishing machine. Easy to manufacture.

FIG. 1 is a cross-sectional view for explaining a method of manufacturing a wiring using copper or a copper alloy.
FIG. 2 is a cross-sectional view for explaining a method of manufacturing a wiring using copper or a copper alloy when an antireflection film is left.
FIG. 3 is a cross-sectional view illustrating dishing.

Hereinafter, embodiments of the present invention will be described in detail.
The present invention provides a metal film embedded on a substrate having a recess so as to cover the recess, or a barrier metal film formed on the substrate having a recess and polishing the metal film embedded so as to cover the recess. A method for producing a plurality of types of polishing compositions having different dishing amounts, wherein the plurality of types of polishing compositions are produced by mixing two kinds of preliminary compositions having different compositions at different mixing ratios. Thus, for example, the polishing composition is a method for producing a plurality of types of polishing compositions so as to give a predetermined dishing amount in the range of 1 to 300 nm.
The two types of preliminary compositions include (a) abrasive grains, (b) oxidizing agents, (c) one or more acids selected from the group consisting of amino acids, organic acids and inorganic acids, and (d It is possible to use a pre-composition (A) containing a surfactant) and a pre-composition (B) containing (a) abrasive grains and (b) an oxidizing agent.
The preliminary composition (B) may further comprise (c) one or more acids selected from the group consisting of amino acids, organic acids, inorganic acids, and (d) a surfactant, The two preliminary compositions (A) and (B) differ in at least one or more concentrations of (a), (b), (c), and (d).
The preliminary compositions (A) and (B) may be mixed at any mixing ratio (that is, one preliminary composition in the final polishing composition prepared by mixing so as to give a predetermined dishing amount in the range of 1 to 300 nm. Can be mixed at a ratio of more than 0% and less than 100% (the ratio of the other premix is less than 100% and more than 0% accordingly).
When producing the polishing composition according to the present invention, it is also possible to change the types of components having the same function between the two pre-mixtures. For example, the abrasive grains contained in one preliminary mixture may be different from the abrasive grains contained in the other preliminary mixture.
Next, the components used in each preliminary composition will be described.
<Abrasive>
In the present invention, abrasives such as silica, alumina, ceria, and organic abrasives can be used as the abrasive grains. These abrasives may be used alone or in combination of two or more. The purpose of these abrasives is to increase the polishing rate sufficiently, but scratches such as scratches may be made on the substrate surface depending on the type of abrasive. A preferable abrasive that suppresses scratches while sufficiently increasing the polishing rate is silica. Further preferred abrasives are those based on colloidal silica produced by hydrolysis from alkoxysilane. The content of these abrasives may be 0.01 to 30% by mass, preferably 0.1 to 20% by mass, and more preferably 0.2 to 10% by mass with respect to the polishing composition at the time of polishing. If the content of the abrasive is too large, scratches may be caused. If the content is too small, the polishing rate cannot be increased sufficiently, or the remaining metal film on the barrier film may not be eliminated. The size of the abrasive is preferably a particle size of 1 μm or less, more preferably 0.01 to 0.5 μm. If the particle size of the abrasive is too small, the polishing rate may not be sufficiently increased, and if it is too large, it may cause scratches on the metal surface such as scratches.
<Oxidizing agent>
The oxidizing agent used in the present invention oxidizes a metal or a metal alloy and contributes to an improvement in the polishing rate. Oxidizing agents include oxygen, ozone, hydrogen peroxide, alkyl peroxides such as t-butyl hydroperoxide and ethylbenzene hydroperoxide, peracids such as peracetic acid and perbenzoic acid, and permanganic acids such as potassium permanganate. Examples thereof include salts, periodates such as potassium periodate, persulfates such as ammonium persulfate and potassium persulfate, hypochlorites such as potassium hypochlorite, and polyoxoacids. As these oxidizing agents, hydrogen peroxide and persulfate which are easy to handle are preferable.
The content of the oxidizing agent may be 0.01 to 30% by mass, preferably 0.05 to 20% by mass, and more preferably 0.1 to 10% by mass with respect to the polishing composition at the time of polishing. If the amount is too small, the polishing rate may become too low. If the amount is too large, the polishing rate may be wasted.
<Acid>
An acid selected from the group consisting of inorganic acids, organic acids and amino acids used in the present invention can be added as an etchant to promote polishing and to perform stable polishing. In the present invention, amino acids are not included in the organic acid. Examples of such inorganic acids include sulfuric acid, phosphoric acid, phosphonic acid, and nitric acid. Organic acids include formic acid, acetic acid, propionic acid, butyric acid, valeric acid, 2-methylbutyric acid, n-hexanoic acid, 3,3-dimethylbutyric acid, 2-ethylbutyric acid, 4-methylpentanoic acid, n-heptanoic acid 2-methylhexanoic acid, n-octanoic acid, 2-ethylhexanoic acid, benzoic acid, glycolic acid, salicylic acid, glyceric acid, succinic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, maleic acid, phthalate Mention may be made of carboxylic acids such as acids, malic acid, tartaric acid, citric acid, lactic acid and their salts. As amino acids, glycine, alanine, β-alanine, 2-aminobutyric acid, norvaline, valine, leucine, norleucine, isoleucine, alloisoleucine, phenylalanine, proline, sarcosine, ornithine, lysine, taurine, serine, threonine, allothreonine. , Homoserine, tyrosine, 3,5-diiodotyrosine, β- (3,4-dihydroxyphenyl) alanine, thyroxine, 4-hydroxyproline, cysteine, methionine, ethionine, lanthionine, cystathionine, cystine, cysteic acid, aspartic acid, Glutamic acid, S- (carboxymethyl) cystine, 4-aminobutyric acid, asparagine, glutamine, azaserine, arginine, canavanine, citrulline, δ-hydroxylysine, creatine, key Renin, histidine, 1-methylhistidine, 3-methylhistidine, ergothioneine, can be mentioned amino acids such as tryptophan.
These acids such as inorganic acids, organic acids and amino acids may be used singly or in combination of two or more. The content of these acids may be 0.01 to 10% by mass, preferably 0.02 to 5% by mass, and more preferably 0.05 to 2% by mass with respect to the polishing composition at the time of polishing. If the amount is too small, it is difficult to obtain a high polishing rate. If the amount is too large, the etching rate of a metal or metal alloy may become too fast. The dishing can be adjusted with acid. However, since acid may induce corrosion, it is preferable to adjust the concentration within a range where corrosion does not occur.
<Surfactant>
One of the surfactants that can be used in the present invention is an alkyl aromatic sulfonic acid having 8 or more carbon atoms. Such alkyl aromatic sulfonic acids include decyl benzene sulfonic acid, undecyl benzene sulfonic acid, dodecyl benzene sulfonic acid, tridecyl benzene sulfonic acid, tetradecyl benzene sulfonic acid or mixtures thereof, alkyl benzene sulfonic acid, alkyl naphthalene. Formalin condensates of sulfonic acid and alkylnaphthalenesulfonic acid can be mentioned. Such an alkyl aromatic sulfonic acid having 8 or more carbon atoms may be a salt such as potassium or ammonium. Of these, dodecylbenzenesulfonic acid is preferred. Such alkyl aromatic sulfonic acids having 8 or more carbon atoms may contain one kind or two or more kinds. The content of aromatic sulfonic acid having 8 or more carbon atoms may be 5% by mass or less, preferably 1% by mass or less, more preferably 0.5% by mass or less, based on the polishing composition at the time of polishing. . It is considered that the alkyl group aromatic sulfonic acid having 8 or more carbon atoms contributes to the improvement of the level difference relaxation property of the metal film. Alkyl aromatic sulfonic acids having 8 or more carbon atoms contribute to dishing reduction by addition.
As the surfactant, a phosphate ester having an alkyl group having 8 or more carbon atoms can also be used. Examples of phosphate esters include octyl phosphate, decyl phosphate, lauryl phosphate, myristyl phosphate, cetyl phosphate, stearyl phosphate, secondary alkyl (average carbon number 13) phosphate, 2-ethylhexyl phosphate, oleyl phosphate, etc. Alkyl phosphate ester, monostearyl glyceryl ether phosphate, monocetyl glyceryl ether phosphate, monooleyl glyceryl ether phosphate, isostearyl glyceryl ether phosphate, polyoxyethylene octyl ether phosphate, polyoxyethylene decyl ether phosphate, poly Oxyethylene lauryl ether phosphate, polyoxyethylene myristyl ether phosphate, polyoxyethylene cetyl ether phosphate, polyoxyethylene stearyl ether phosphate, polyoxyethylene secondary alkyl ( Equalizing carbons 13) ether phosphate, polyoxyethylene 2-ethylhexyl ether phosphate, polyoxyethylene 2 oleyl ether phosphate, polyoxyalkylene ether alkyl phosphate esters such as polyoxyethylene nonylphenyl ether phosphate. Such a phosphate ester may be a salt such as potassium or ammonium, and may be a primary, secondary, tertiary ester or a mixture thereof. Preferably, alkyl phosphoric acid having 8 to 18 carbon atoms such as octyl phosphoric acid, lauryl phosphoric acid, stearyl phosphoric acid, polyoxyethylene lauryl ether phosphoric acid, polyoxyethylene secondary alkyl (average 13 carbon atoms) ether phosphoric acid, etc. A polyoxyalkylene ether phosphate. More preferably, it is a C10-15 polyoxyalkylene ether phosphate.
The phosphate ester having an alkyl group having 8 or more carbon atoms used in the present invention may contain one kind or two or more kinds. The content of these compounds in the polishing composition at the time of polishing may be 5% by mass or less, preferably 1% by mass or less, and more preferably 0.5% by mass or less. Such phosphate ester or polyoxyalkylene ether phosphate ester exhibits dishing suppression, but if it is added in a small amount, the effect of suppressing dishing is small, and when it is added in a large amount, dishing can be reduced but a high polishing rate is required. However, it is difficult to apply in practical performance.
As the surfactant, a fatty acid having 8 or more carbon atoms can be further used. This fatty acid having 8 or more carbon atoms suppresses surface roughness of the metal film during polishing, either alone or in combination with an azole group-containing compound having a molecular weight of 300 to 15000 having 3 or more azole groups in the molecule. Such fatty acids having 8 or more carbon atoms include caprylic acid, pelargonic acid, capric acid, lauric acid, myristic acid, pentadecylic acid, palmitic acid, margaric acid, stearic acid, arachidic acid, behenic acid, lignoceric acid, and serotic acid. , Saturated fatty acids such as montanic acid and melicic acid, and unsaturated fatty acids such as eicosapentaenoic acid, oleic acid, linoleic acid, and linolenic acid. These may be salts such as potassium and ammonium, and may contain one kind or two or more kinds. Of these, oleic acid is preferable. Oleic acid may be used alone, or a mixture of fatty acids in which 50% by mass or more is oleic acid may be used. The content of the fatty acid having 8 or more carbon atoms may be 5% by mass or less, preferably 1% by mass or less, and more preferably 0.5% by mass or less as a concentration during polishing. If the amount is too large, a metal film residue on the barrier film may be generated. Therefore, it is preferable to contain the minimum amount that sufficiently reduces the surface roughness of the metal film.
In addition to the surfactant, any other cationic, anionic and nonionic surfactants can be used. Examples of the cationic surfactant include aliphatic amines or salts thereof, and aliphatic ammonium salts. Examples of the anionic surfactant include alkyl ether carboxylic acids or salts thereof, sulfate compounds such as higher alcohol sulfates, alkyl ether sulfates or salts thereof, and the like. Examples of the nonionic surfactant include ether types such as polyoxyethylene alkyl ether, ether ester types such as glycerol ester polyoxyethylene ether, and ester types such as polyethylene glycol fatty acid ester, glycerol ester, and sorbitan ester.
A water-soluble polymer can be further added to the polishing composition of the present invention. Examples of water-soluble polymers include polyacrylic acid, polymethacrylic acid and ammonium salts thereof, polyisopropylacrylamide, polydimethylacrylamide, polymethacrylamide, polymethoxyethylene, polyvinyl alcohol, hydroxyethylcellulose, carboxymethylcellulose, carboxyethylcellulose, and polyvinylpyrrolidone. It is done.
The content of the water-soluble polymer and the other surfactant is preferably 5% by mass or less with respect to the polishing composition at the time of polishing. More preferably, it is 1 mass% or less, Most preferably, it is 0.5 mass% or less.
<Azole group-containing compound>
The polishing composition of the present invention can be added with an azole group-containing compound having a molecular weight of 300 to 15000 having 3 or more azole groups in the molecule by being included in one or both of the two types of preliminary compositions. .
The azole group-containing compound having a molecular weight of 300 to 15000 having 3 or more azole groups in the molecule is an azole group-containing compound having 3 or more azole groups in one molecule, and can be produced by various methods. Azoles include imidazole, triazole, tetrazole, and thiazole, and some of them have reactive substituents such as hydroxyl group, carboxyl group, and amino group. For example, 4-carboxyl-1H-benzotriazole, 4-hydroxybenzotriazole, 2-aminoimidazole, etc. are mentioned. Among these, a carboxyl group reacts with a polyhydric alcohol and a polyvalent amine to produce an ester and an amide, respectively. At this time, a compound having three or more azoles can be produced by using a trivalent or higher compound as the polyhydric alcohol or polyvalent amine. Similarly, a compound having three or more azole groups can be produced by reacting a azole having a hydroxyl group or an amino group with a compound having a site that reacts with them.
Moreover, the azole group containing compound used by this invention can also be manufactured by superposing | polymerizing the azole which has a vinyl group. Examples of the azole having a vinyl group include 1-vinylimidazole and 2- [3- (2H-benzotriazol-1-yl) -4-hydroxyphenyl] ethyl methacrylate.
Of these azole group-containing compounds, a polymer containing an azole unit having a vinyl group is preferred. This polymer is obtained by polymerizing an azole having a vinyl group. An azole having a vinyl group may be polymerized alone or may be copolymerized with other vinyl compounds.
Specifically, the azole group-containing compound can be synthesized such that the molecular weight per azole group of the azole group-containing compound is 90 to 300, particularly preferably 90 to 200.
Examples of vinyl compounds that can be copolymerized with azoles having vinyl groups include acrylic acid, methacrylic acid, methyl acrylate, methyl methacrylate, acrylamide, N-vinylacetamide, N-vinylformamide, acryloylmorpholine, N-vinylpyrrolidone, and vinyl acetate. And styrene.
As a method for polymerizing such a vinyl compound, radical polymerization in an aqueous solution or an organic solvent is generally used. Polymerize using radical initiator such as azobisisobutyronitrile, but adjust molecular weight with chain transfer agent such as dodecyl mercaptan, trimethylolpropane tris (3-mercaptopropionate), α-methylstyrene dimer You can also.
As the molecular weight of such a polymer, those having a mass average molecular weight of 300 to 15000 can be used. Preferably, it is 500-10000, More preferably, it is 2000-8000, More preferably, it is 4500-6500.
The content of the azole group-containing compound used in the present invention in the polishing composition may be 0.001 to 1% by mass, preferably 0.002 to 0.5% by mass, and more preferably 0.003 to 0%. .1% by mass. Dishing adjustment is also possible with azole group-containing compounds.
The polishing composition of the present invention can be used in any of an organic solvent composition, an organic solvent / water mixture composition, and an aqueous composition. However, in consideration of cost, usability, etc., the polishing composition may be an aqueous solution. desirable. Therefore, it is desirable that the azole group-containing compound used in the present invention is also water-soluble. In order to produce the polishing composition of the present invention, two preliminary compositions having a high concentration can be prepared, mixed and diluted to prepare a polishing composition used for polishing. Therefore, the solubility of the azole group-containing compound used in the present invention in water is preferably 0.01% by mass or more, more preferably 0.03% by mass or more.
It is known that the azole group used in the present invention interacts with a metal such as copper, and this is considered to have reduced step relief and dishing. Further, the azole group-containing compound used in the present invention can control the polishing rate of a barrier film such as tantalum, which is considered to be effective for obtaining a small erosion characteristic. On the other hand, a basic compound such as ethanolamine generally used for controlling the polishing rate of the barrier film similarly reduces erosion, but increases step relief and dishing. In the present invention, by using an azole group-containing compound having a molecular weight of 300 to 15000 having 3 or more azole groups, a complex action is caused, and the contradictory functions of reducing step relief, dishing and erosion are reduced at a time. I think it was possible. In addition, an azole group-containing compound having three or more azole groups having a molecular weight of more than 15000 is liable to cause a metal residue on a barrier film, for example, other than a wiring in polishing a wiring metal, and the use of a barrier film polishing slurry is limited. There is.
<Other ingredients>
The polishing composition of the present invention can further contain an anticorrosive agent (protective film forming agent). If an anticorrosive is used, it can be included in one or both of the preliminary compositions (A) and (B). Components that can be used as anticorrosives include benzimidazole-2-thiol, 2- [2- (benzothiazolyl)] thiopropionic acid, 2- [2- (benzothiazolyl) thiobutyric acid, 2-mercaptobenzothiazole, 1,2 , 3-triazole, 1,2,4-triazole, 3-amino-1H-1,2,4-triazole, benzotriazole, 1-hydroxybenzotriazole, 1-dihydroxypropylbenzotriazole, 2,3-dicarboxypropyl Benzotriazole, 4-hydroxybenzotriazole, 4-carboxyl-1H-benzotriazole, 4-methoxycarbonyl-1H-benzotriazole, 4-butoxycarbonyl-1H-benzotriazole, 4-octyloxycarbonyl-1H-benzotriazo , 5-hexylbenzotriazole, N- (1,2,3-benzotriazolyl-1-methyl) -N- (1,2,4-triazolyl-1-methyl) -2-ethylhexylamine, tolyltriazole An azole such as naphthotriazole, bis [(1-benzotriazolyl) methyl] phosphonic acid, benzimidazole, tetrazole or a salt thereof is preferable. More preferred are benzotriazole, tolyltriazole, hydroxybenzotriazole, carboxybenzotriazole, benzimidazole, tetrazole and quinaldic acid. The content of the anticorrosive may be 5% by mass or less, preferably 2% by mass or less, and more preferably 0.5% by mass or less, based on the polishing composition at the time of polishing. Inclusion of such an anticorrosive agent is effective for preventing the metal film surface from getting dirty.
In the present invention, alkali can be added to the polishing composition as long as it does not adversely affect performance and physical properties. The alkali can be included in one or both of the preliminary compositions (A) and (B). Alkali is used for the purpose of maintaining stable polishing performance, a pH adjuster, and a buffer. Examples of such alkali include ammonia, sodium hydroxide, potassium hydroxide, potassium carbonate, potassium bicarbonate, ammonium bicarbonate, methylamine, ethylamine, propylamine, isopropylamine, butylamine, isobutylamine, t-butylamine, amylamine, Monoamines having hydroxyl groups such as alkyl monoamines such as allylamine, 2-ethylhexylamine, cyclohexylamine, benzylamine, furfurylamine, O-aminophenol, ethanolamine, 3-amino-1-propanol, 2-amino-1-propanol , Ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, O-phenylenediamine, trimethylene Amine, 2,2-diaminodi-n-propylamine, 2-methyl-2- (2-benzylthioethyl) ethylenediamine, 1,5-diamino-3-pentanol, 1,3-diamino-2-propanol, xylenediamine And diamines such as bisaminopropyl polyalkylene ether, polyamines such as polyallylamine and polyethyleneimine. Of these alkalis, ammonia, potassium hydroxide, ethylenediamine, and propylenediamine are preferable. The addition of alkali may be 10% by mass or less, preferably 5% by mass or less, and more preferably 1% by mass or less with respect to the polishing composition. Such alkalis do not affect dishing, but are generally additives that can increase dishing.
<Use of polishing composition>
The polishing composition used in the present invention is preferably used between pH 2 and 12. More preferably, it is pH 3-11, More preferably, it is pH 5-10. Thus, the inorganic acid, the organic acid, and the alkali can be used as a reagent for adjusting the pH.
The polishing composition used in the present invention can be preferably used in the range of 0 to 100 ° C. Generally, the vicinity of room temperature to be used is preferable, but it is also possible to adjust the temperature of the polishing composition for the purpose of adjusting the polishing rate. If the temperature is too low, the polishing rate will not increase, and if it is 0 ° C. or lower, it may freeze. In addition, side reactions may occur when the temperature is high. Preferably, it is 10-50 degreeC, More preferably, it is 15-40 degreeC.
The dripping amount of the polishing composition used in the present invention to the polishing machine is determined by the size of the polishing machine and the wafer. When an 8-inch wafer (200 mm wafer) is used, it can be used at 10 to 1000 ml / min. Preferably, it is 50-500 ml / min, More preferably, it is 100-400 ml / min.
Examples of the object to be polished to which the polishing composition of the present invention is preferably used include metals, and specific examples of preferable metals include platinum group metals such as aluminum, copper, iron, tungsten, nickel, tantalum, ruthenium and platinum, or These metal alloys are mentioned. Particularly preferred is a metal film that covers the wiring part or the wiring part of the multilayer wiring part, and is buried on the substrate having the concave part so as to cover the concave part. More preferably, it can be used for copper or copper alloy, iron or iron alloy which becomes the wiring part of the multilayer wiring part. In this case, a barrier film may be formed between the wiring metal film and the substrate. In this case, the barrier film can be polished together with the metal film. As such a barrier film material, tantalum, tantalum alloy, tantalum nitride, titanium, titanium alloy or the like is preferably used. In some cases, a cap material or an antireflection film is interposed between the barrier film and the interlayer insulating film. The film thickness is about several tens to 100 nm.
As a polishing method using the polishing composition of the present invention, for example, a substrate having a metal film to be polished is pressed against the polishing cloth while supplying the polishing composition of the present invention onto the polishing cloth of the polishing surface plate. A method of polishing a metal film to be polished by relatively moving the polishing surface plate and the substrate can be mentioned. As a polishing apparatus, a general polishing apparatus having a holder for holding a semiconductor substrate and a surface plate on which a polishing cloth is attached can be used. Since the rotation speed of the polishing platen is completely different depending on the structure and size of the polishing machine, it is difficult to specify here, but polishing is performed at 10 to 500 m / min. Preferably, it is 20-300 m / min, More preferably, it is 30-150 m / min. In order to maintain the uniformity of substrate polishing by rotating the polishing platen, it is necessary to rotate the substrate. The substrate has the same rotational speed as the polishing surface plate, but the rotational speed may be slightly reduced or increased in order to obtain uniformity. Further, the substrate is pressed against the polishing cloth through the holder, and the pressure at this time can be 0.1 to 100 KPa. Since the pressure tends to be low when the rotation speed of the polishing platen is high, it is difficult to specify, but it is preferably 0.5 to 80 KPa, more preferably 1 to 50 KPa.
As the polishing cloth, a general nonwoven fabric, foamed polyurethane, or the like can be used. Many polishing cloths are provided with grooves for the purpose of increasing the polishing rate or improving the discharge of slurry. There are XY grooves, K grooves and the like, and any of the grooves can be used for the polishing composition of the present invention. Moreover, in order to prevent clogging and to perform stable polishing, the polishing cloth is dressed with a dresser with diamond or the like, and a generally known method can be used.
As a method for supplying the polishing composition of the present invention onto the polishing cloth of the polishing surface plate, it is continuously supplied with a pump or the like. At this time, the polishing composition may be supplied as one liquid containing all components, and further, each preliminary composition may be supplied in a separate line. When supplying two or more liquids in separate lines, they can be supplied as a single liquid immediately before the polishing cloth, or they can be supplied as they are on the polishing cloth as they are and mixed while being polished.
Each preliminary composition used in the present invention may be divided into a plurality of parts and / or transported and stored as a concentrated composition in consideration of convenience of handling such as liquid stability. For example, it can be divided into two stock solutions of an oxidizer and other solutions, or the stock solutions of components other than the oxidizer are divided into those mainly composed of abrasive grains and those other than that, for a total of 3 stock solutions It can be. By combining the undiluted solutions in this way, these undiluted solutions may be mixed and diluted if necessary to form a preliminary composition and further a kit that becomes a polishing composition used for polishing. Further, the preliminary composition may be a thicker composition (for example, 2 to 5 times) as described above, and may be diluted with water or the like at the time of production of the polishing composition so as to have a concentration suitable for polishing.
By using the polishing composition produced by the method of the present invention, a substrate having a flat metal film can be produced. This process will be further described as a method of forming wiring on the element. First, a groove and an opening for forming a wiring are opened in the interlayer insulating film on the substrate, and a thin barrier film is formed on the insulating film. Furthermore, a metal film for metal wiring such as copper is formed by a method such as plating so as to fill the groove and the opening. By polishing this metal film and, if necessary, further polishing and flattening the barrier film and the interlayer insulating film, a substrate with the metal film flattened can be manufactured.
A method for forming a wiring in the MRAM by using the polishing composition produced by the method of the present invention will be described. The metal wiring is composed of a conductor layer made of aluminum or aluminum alloy, or copper or copper alloy, and a ferromagnetic layer such as nickel-iron (permalloy) so as to surround the conductor layer. If necessary, a barrier film such as tantalum or tantalum nitride is formed thin so as to sandwich the ferromagnetic layer. This metal wiring is formed by the damascene method, but the extra conductor layer, ferromagnetic layer and barrier film are planarized and removed while polishing.
The interlayer insulating film here is made of an inorganic interlayer insulating film containing a large amount of silicon such as a silicon oxide film, hydroxysilsesquioxane (HSQ), methylsilsesquioxane (MSQ), or benzocyclobutene. An organic interlayer insulating film such as a film, and a low dielectric constant interlayer insulating film in which pores are provided can also be used.

表１に示した組成のうちの一つを予備組成物（Ａ）、もう一つを予備組成物（Ｂ）として、表２に示すとおりの研磨組成物１〜１５を調製した。単一の予備混合物のみを使用する研磨組成物１、５、９は対照例である。研磨組成物１〜４は、砥粒、酸化剤、有機酸、界面活性剤、アゾール化合物及び防食材を含む組成１を予備組成物（Ａ）とし、砥粒、酸化剤、有機酸、界面活性剤及びアゾール化合物を含む組成２を予備組成物（Ｂ）として、それらを混合して研磨した。ディッシングは対照例１の１１ｎｍから８３ｎｍまで変化することができた。また、この範囲では研磨レートに大きな変化はなかった。研磨組成物５〜８は、組成１の防食材量を増やした組成３を予備組成物（Ａ）とし、組成２を予備組成物（Ｂ）として用いた。これらの研磨組成物でも、研磨組成物１〜４に比べてやや小さいディッシングであるが、対照例４の４ｎｍから１２５ｎｍまでコントロールできた。研磨組成物９〜１１は、砥粒、酸化剤、有機酸、界面活性剤、アゾール化合物及び防食材を含む組成４を予備組成物（Ａ）とし、組成４にアルカリとして更にプロピレンジアミンを添加した組成５を予備組成物（Ｂ）として用いた。ディッシングは、対照例９の１４ｎｍから７１ｎｍまで変化することができた。実施例１４、１５は、組成１を予備組成物（Ａ）、組成１の酸化剤である過硫酸アンモニウムの量を増加させた組成７を予備組成物（Ｂ）として用いた。対照例１と対比して、２つの予備組成物を混合して製造した研磨組成物の全体での酸化剤の濃度を変えることによっても、ディッシングをコントロールできることが示された。実施例１２、１３は、組成１を予備組成物（Ａ）、組成１の酸化剤及び砥粒以外を除いた組成６を予備組成物（Ｂ）として用いた。これは実質的に砥粒、酸化剤以外を水で希釈する方法である。対照例１と対比して、この方法でもディッシングはコントロールされる。特に、予備組成物の混合比とディッシング量とが比較的直線的な関係となる予備組成物１と２の組み合わせ、予備組成物３と２の組み合わせ、および予備組成物４と５の組み合わせは、ディッシングのコントロールがしやすく好ましい。

（実施例２）
分子量５０００の化合物Ｅをアゾール化合物として用いた。
研磨機はアプライドマテリアル社製Ｍｉｒｒａを用いて、８インチウェハの評価を行った。基板と研磨定盤との相対速度は７５ｍ／分、研磨組成物供給速度は２００ｍｌ／分、圧力は１４ｋＰａで研磨を行った。
研磨パッドはロデールニッタ社製ＩＣ１０００（ｋ−ＸＹグルーブ）を用いた。研磨組成物を製造するのに、表３に示した組成の予備組成物を使用した。各組成の表に示した成分以外は水であり、表中の各成分量は水を含めた組成物全体の質量に対する質量％で示した。使用したアンモニアは、表中のｐＨを与えるだけの量を使用した。ここで、ＡＰＳは過硫酸アンモニウム、ＤＢＳはドデシルベンゼンスルホン酸、ＰＯＥはポリオキシエチレン２級アルキルエーテルリン酸エステル、ＯＬＡはオレイン酸、ＢＺＩはベンズイミダゾールを示す。砥粒のシリカは粒子径１２０ｎｍのコロイダルシリカを用いた。

表３に示した組成のうちの一つを予備組成物（Ａ）、もう一つを予備組成物（Ｂ）として、表４に示すとおりの研磨組成物１６〜２５を調製した。単一の予備混合物のみを使用する研磨組成物１６、２０、２１、２５は対照例である。研磨組成物１６〜２０は、砥粒、酸化剤、有機酸、界面活性剤、防食材及びアゾールを三個以上有する化合物を含む組成８を予備組成物（Ａ）として用い、予備組成物（Ｂ）としては組成８のアゾールを三個以上有する化合物を０．０２質量％から０．０７質量％に増加した組成９を用いた。研磨組成物２１〜２５は、組成８と９の防食材の添加量を増やした組成１０と組成１１をそれぞれ予備組成物（Ａ）及び（Ｂ）として用いた。どちらの事例でも、ディッシングのコントロールが可能であった。

（実施例３）
分子量５０００の化合物Ｅをアゾール化合物として用いた。
研磨機はアプライドマテリアル社製Ｍｉｒｒａを用いて、８インチウェハの評価を行った。基板と研磨定盤との相対速度は７５ｍ／分、研磨組成物供給速度は２００ｍｌ／分、圧力は１４ｋＰａで研磨を行った。
研磨パッドはロデールニッタ社製ＩＣ１０００（ｋ−ＸＹグルーブ）を用いた。研磨組成物を製造するのに、表５に示した組成の予備組成物を使用した。各組成の表に示した成分以外は水であり、表中の各成分量は水を含めた組成物全体の質量に対する質量％で示した。ここで、ＡＰＳは過硫酸アンモニウム、ＤＢＳはドデシルベンゼンスルホン酸、ＰＯＥはポリオキシエチレン２級アルキルエーテルリン酸エステル、ＯＬＡはオレイン酸、ＢＺＩはベンズイミダゾールを示す。砥粒のコロイダルシリカは粒子径１２０ｎｍのものを用いた。

表５に示した組成のうちの一つを予備組成物Ａ、もう一つを予備組成物Ｂとして、表６に示すとおりの研磨組成物２６〜３５を調製した。単一の予備混合物のみを使用する研磨組成物２６、３０、３１、３５は対照例である。研磨組成物２６〜３０は、砥粒、酸化剤、有機酸、界面活性剤、防食材及びアゾールを三個以上有する化合物を含む組成１２を予備組成物（Ａ）として用い、予備組成物（Ｂ）としては組成１２のアゾールを三個以上有する化合物を０．０４質量％から０．０８質量％に増加した組成１３を用いた。研磨組成物３１〜３５は、組成１２と１３の砥粒の添加量を増やした組成１４と組成１５をそれぞれ予備組成物（Ａ）及び（Ｂ）として用いた。どちらの事例でも、ディッシングのコントロールが可能であった。また、コロイダルシリカ量が多いほど、ディッシングは大きくなり、砥粒であるコロイダルシリカの量でもディッシングがコントロールできることが示された。

（実施例４）
研磨機はアプライドマテリアル社製Ｍｉｒｒａを用いて、８インチウェハの評価を行った。基板と研磨定盤との相対速度は７５ｍ／分、研磨組成物供給速度は１５０ｍｌ／分、圧力は１４ｋＰａで研磨を行った。
研磨パッドはロデールニッタ社製ＩＣ１０００（ｋ−ＸＹグルーブ）を用いた。表７に示した組成の予備組成物を使用して、表８に示した研磨組成物を製造した。各組成の表に示した成分以外は水であり、表中の各成分量は水を含めた組成物全体の質量に対する質量％で示した。使用したアンモニアは、表中のｐＨを与えるだけの量を使用した。ここで、ＡＰＳは過硫酸アンモニウム、ＤＢＳはドデシルベンゼンスルホン酸、ＯＬＡはオレイン酸を示す。砥粒のシリカは粒子径１２０ｎｍのコロイダルシリカを用いた。

組成１６、１７は、砥粒、酸化剤、酸（有機酸）、界面活性剤を含み、予備組成物（Ａ）と予備組成物（Ｂ）は界面活性剤ＤＢＳの量が異なる。ＤＢＳの量が少なくなるほどディッシングは小さくなり、コントロールすることができる。

EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated further in detail, this invention is not limited to these Examples at all.
(Synthesis example)
Hereinafter, although the synthesis example of the azole group containing compound which has 3 or more of azole groups is shown, this invention is not limited to these synthesis examples at all.
A 500 ml flask equipped with a thermometer, a stirrer, a nitrogen inlet tube and a reflux condenser was charged with 40 g of 2-propanol and heated to the reflux temperature (about 83 ° C.) while stirring in a nitrogen atmosphere. A solution prepared by dissolving 46.31 g of 1-vinylimidazole, 43.69 g of N-vinylpyrrolidone and 1.46 g of α-methylstyrene dimer in 28.5 g of 2-propanol in 78 g of 2-propanol (hereinafter, monomer solution) And 2.45 g of dimethyl 2,2′-azobis (2-methylpropionate) dissolved in 213.55 g of 2-propanol (hereinafter referred to as initiator solution 1) were added with a metering pump. The addition time is 4 hours for the monomer solution and 7 hours for the initiator solution 1. The reaction was continued for 1 hour after the addition of the initiator solution 1, and then a solution obtained by dissolving 0.21 g of dimethyl 2,2′-azobis (2-methylpropionate) in 6.59 g of 2-propanol (hereinafter referred to as initiator solution 2). Added). The operation of adding the same initiator solution 2 every 1 hour of reaction (initiator additional addition operation) was repeated 5 more times, and then the reaction was continued for 4 hours. After cooling to room temperature, about 380 g of a brown transparent solution was obtained. This brown transparent solution was concentrated by a rotary vacuum evaporator, and water dissolution was repeated twice to replace the solvent from 2-propanol with water. The solid concentration was 15% and was used for slurry preparation without isolation.
The molecular weight of the synthesized compound (hereinafter sometimes referred to as “Compound E”) was measured in terms of polyethylene glycol using gel permeation chromatography (GPC). The molecular weight was 5000.
<Wafer>
Blanket wafer: A silicon wafer with a copper film and a tantalum film (barrier film) uniformly attached.
Pattern wafer: A silicon wafer having a groove depth of 500 nm, a thickness of 25 nm, tantalum formed as a barrier film, and a copper film of 1000 nm (see the upper diagram in FIG. 1).
<Polishing 8 inch wafers>
Relative speed between substrate and polishing surface plate: 70 m / min Polishing pad: IC1000 / SUBA400 manufactured by Rodel Nitta
Polishing composition supply rate: 200 ml / min <Polishing property evaluation>
Step measurement: A palpation type step meter was used.
Blanket copper, tantalum film thickness measurement: Measured from sheet resistance.
Pattern copper film thickness measurement: It measured from the sheet resistance of the copper film without the pattern of the site | part vicinity to evaluate.
Measurement of polishing rate: The copper film and the barrier film thickness were measured from the electrical resistance values before and after polishing, and converted from the polishing time.
Polishing of pattern wafer: When Mirra manufactured by Applied Materials was used as a polishing machine, the end point was detected with a standard end point detector, and polishing was terminated when overpolishing was performed for 20 seconds.
Evaluation of dishing: As shown in FIG. 3, the step d between the 100 μm space portion 3 ″ and the 100 μm line portion 2 ″ formed on the silicon wafer 1 was evaluated as dishing.
Example 1
Compound E having a molecular weight of 5000 was used as the azole compound.
The polishing machine evaluated the 8-inch wafer using Mirara manufactured by Applied Materials. Polishing was performed at a relative speed of 75 m / min between the substrate and the polishing surface plate, a polishing composition supply speed of 200 ml / min, and a pressure of 14 kPa.
As a polishing pad, IC1000 (k-XY groove) manufactured by Rodel Nitta was used. To prepare the polishing composition, a preliminary composition having the composition shown in Table 1 was used. The components other than those shown in the table of each composition are water, and the amount of each component in the table is shown by mass% with respect to the mass of the entire composition including water. Of the alkali used, ammonia was used in an amount sufficient to give the pH in the table. Here, APS is ammonium persulfate, DBS is dodecylbenzenesulfonic acid, POE is polyoxyethylene secondary alkyl ether phosphate ester, OLA is oleic acid, BZI is benzimidazole, and PDA is propylenediamine. Colloidal silica having a particle size of 120 nm was used as the abrasive silica.

Polishing compositions 1 to 15 as shown in Table 2 were prepared using one of the compositions shown in Table 1 as the preliminary composition (A) and the other as the preliminary composition (B). Polishing compositions 1, 5, and 9 using only a single premix are control examples. Polishing compositions 1 to 4 use the composition 1 containing abrasive grains, an oxidizing agent, an organic acid, a surfactant, an azole compound and an anticorrosive as a preliminary composition (A), and the abrasive grains, the oxidizing agent, the organic acid, and the surface activity. The composition 2 containing the agent and the azole compound was used as a preliminary composition (B), and they were mixed and polished. The dishing could vary from 11 nm to 83 nm in Control Example 1. In this range, there was no significant change in the polishing rate. Polishing composition 5-8 used the composition 3 which increased the amount of anticorrosives of the composition 1 as the preliminary composition (A), and used the composition 2 as the preliminary composition (B). Even with these polishing compositions, the dishing was slightly smaller than that of the polishing compositions 1 to 4, but it was possible to control from 4 nm to 125 nm of the control example 4. Polishing composition 9-11 made the composition 4 containing an abrasive grain, an oxidizing agent, an organic acid, surfactant, an azole compound, and an anticorrosive material as a preliminary composition (A), and also added propylenediamine as an alkali to the composition 4. Composition 5 was used as a preliminary composition (B). The dishing could vary from 14 nm to 71 nm in Control Example 9. In Examples 14 and 15, the composition 1 was used as the preliminary composition (A), and the composition 7 in which the amount of ammonium persulfate as the oxidizing agent of the composition 1 was increased was used as the preliminary composition (B). In contrast to Control Example 1, it was shown that dishing can also be controlled by changing the concentration of oxidizer in the polishing composition produced by mixing two preliminary compositions. In Examples 12 and 13, composition 1 was used as the preliminary composition (A), and composition 6 except the oxidizing agent and abrasive grains of composition 1 was used as the preliminary composition (B). This is a method of substantially diluting other than abrasive grains and an oxidizing agent with water. In contrast to Control 1, dishing is also controlled in this way. In particular, the combination of preliminary compositions 1 and 2, the combination of preliminary compositions 3 and 2, and the combination of preliminary compositions 4 and 5 in which the mixing ratio of the preliminary composition and dishing amount are in a relatively linear relationship, It is preferable because it is easy to control dishing.

(Example 2)
Compound E having a molecular weight of 5000 was used as the azole compound.
The polishing machine evaluated the 8-inch wafer using Mirara manufactured by Applied Materials. Polishing was performed at a relative speed of 75 m / min between the substrate and the polishing surface plate, a polishing composition supply speed of 200 ml / min, and a pressure of 14 kPa.
As a polishing pad, IC1000 (k-XY groove) manufactured by Rodel Nitta was used. To prepare the polishing composition, a preliminary composition having the composition shown in Table 3 was used. The components other than those shown in the table of each composition are water, and the amount of each component in the table is shown by mass% with respect to the mass of the entire composition including water. The amount of ammonia used was sufficient to give the pH in the table. Here, APS represents ammonium persulfate, DBS represents dodecylbenzenesulfonic acid, POE represents polyoxyethylene secondary alkyl ether phosphate ester, OLA represents oleic acid, and BZI represents benzimidazole. Colloidal silica having a particle size of 120 nm was used as the abrasive silica.

Polishing compositions 16 to 25 as shown in Table 4 were prepared using one of the compositions shown in Table 3 as the preliminary composition (A) and the other as the preliminary composition (B). Polishing compositions 16, 20, 21, 25 using only a single premix are controls. Polishing composition 16-20 uses the composition 8 containing the compound which has three or more of an abrasive grain, an oxidizing agent, an organic acid, surfactant, anticorrosive material, and an azole as a preliminary composition (A), and uses a preliminary composition (B ) Was used as composition 9 in which the compound having three or more azoles of composition 8 was increased from 0.02 mass% to 0.07 mass%. As the polishing compositions 21 to 25, the compositions 10 and 11 in which the addition amounts of the anticorrosive materials of the compositions 8 and 9 were increased were used as the preliminary compositions (A) and (B), respectively. In both cases, dishing control was possible.

(Example 3)
Compound E having a molecular weight of 5000 was used as the azole compound.
The polishing machine evaluated the 8-inch wafer using Mirara manufactured by Applied Materials. Polishing was performed at a relative speed of 75 m / min between the substrate and the polishing surface plate, a polishing composition supply speed of 200 ml / min, and a pressure of 14 kPa.
As a polishing pad, IC1000 (k-XY groove) manufactured by Rodel Nitta was used. To prepare the polishing composition, a preliminary composition having the composition shown in Table 5 was used. The components other than those shown in the table of each composition are water, and the amount of each component in the table is shown by mass% with respect to the mass of the entire composition including water. Here, APS represents ammonium persulfate, DBS represents dodecylbenzenesulfonic acid, POE represents polyoxyethylene secondary alkyl ether phosphate ester, OLA represents oleic acid, and BZI represents benzimidazole. The colloidal silica used for the abrasive grains had a particle diameter of 120 nm.

Polishing compositions 26 to 35 as shown in Table 6 were prepared with one of the compositions shown in Table 5 as the preliminary composition A and the other as the preliminary composition B. Polishing compositions 26, 30, 31, 35 using only a single premix are controls. Polishing composition 26-30 uses the composition 12 containing the compound which has three or more of an abrasive grain, an oxidizing agent, organic acid, surfactant, anticorrosive, and an azole as a preliminary composition (A), and a preliminary composition (B ) Was used as composition 13 in which the compound having three or more azoles of composition 12 was increased from 0.04% by mass to 0.08% by mass. As the polishing compositions 31 to 35, the composition 14 and the composition 15 in which the addition amounts of the abrasive grains of the compositions 12 and 13 were increased were used as the preliminary compositions (A) and (B), respectively. In both cases, dishing control was possible. Moreover, it was shown that dishing became large and the dishing was controllable also by the quantity of the colloidal silica which is an abrasive grain, so that there was much colloidal silica amount.

Example 4
The polishing machine evaluated the 8-inch wafer using Mirara manufactured by Applied Materials. Polishing was performed at a relative speed of the substrate and the polishing platen of 75 m / min, a polishing composition supply speed of 150 ml / min, and a pressure of 14 kPa.
As a polishing pad, IC1000 (k-XY groove) manufactured by Rodel Nitta was used. The polishing composition shown in Table 8 was produced using the preliminary composition having the composition shown in Table 7. The components other than those shown in the table of each composition are water, and the amount of each component in the table is shown by mass% with respect to the mass of the entire composition including water. The amount of ammonia used was sufficient to give the pH in the table. Here, APS represents ammonium persulfate, DBS represents dodecylbenzenesulfonic acid, and OLA represents oleic acid. Colloidal silica having a particle size of 120 nm was used as the abrasive silica.

Compositions 16 and 17 include abrasive grains, an oxidizing agent, an acid (organic acid), and a surfactant, and the amount of the surfactant DBS differs between the preliminary composition (A) and the preliminary composition (B). As the amount of DBS decreases, dishing decreases and can be controlled.

Claims (14)

A dishing amount for polishing a metal film embedded on a substrate having a recess so as to cover the recess, or forming a barrier metal film on a substrate having a recess, and polishing the metal film embedded so as to cover the recess. A method for producing different types of polishing compositions, wherein the plurality of types of polishing compositions are mixed with two types of preliminary compositions (A) and (B) having different compositions at different mixing ratios. As a preliminary composition (A), one or more acids selected from the group consisting of (a) abrasive grains, (b) oxidizing agents, (c) amino acids, organic acids, and inorganic acids, (D) A composition containing a surfactant is used, and as the preliminary composition (B), (a) abrasive grains, (b) a composition containing an oxidizing agent is used , and one preliminary composition (A) Further contains an anticorrosive agent, and the pH of the produced polishing composition is 5 to 11 The method for producing plural kinds of abrasive compositions provide different amount of dishing.   The preliminary composition (B) further comprises (c) one or more acids selected from the group consisting of amino acids, organic acids and inorganic acids, (d) a surfactant, and the preliminary composition (A) 2. The method for producing a plurality of types of polishing compositions according to claim 1, wherein in the preliminary composition (B), at least one or more concentrations of (a), (b), (c), and (d) are different.   The method for producing a plurality of types of polishing compositions according to claim 2, wherein the concentration of the abrasive grains (a) of the preliminary composition (A) is higher than that of the preliminary composition (B).   The method for producing a plurality of types of polishing compositions according to claim 2, wherein the concentration of the oxidizing agent (b) in the preliminary composition (A) is lower than that in the preliminary composition (B).   The concentration of one or more acids (c) selected from the group consisting of amino acids, organic acids and inorganic acids in the preliminary composition (A) is lower than that in the preliminary composition (B). A method for producing a plurality of types of polishing compositions described in 1.   The method for producing a plurality of polishing compositions according to claim 2, wherein the concentration of the surfactant (d) in the preliminary composition (A) is higher than that in the preliminary composition (B). The method for producing a plurality of types of polishing compositions according to claim 1, wherein the preliminary composition (A ) further comprises an azole group-containing compound having a molecular weight of 300 to 15000 having 3 or more azole groups in the molecule. . The method for producing a plurality of types of polishing compositions according to claim 1 , wherein the anticorrosive is benzotriazole, tolyltriazole, hydroxybenzotriazole, carboxybenzotriazole, benzimidazole, tetrazole, or quinaldic acid.   The method for producing a plurality of types of polishing compositions according to claim 1, wherein one or both of the preliminary compositions (A) and (B) further contains an alkali.   1 type or 2 types selected from the group in which the surfactant is an alkyl aromatic sulfonic acid having 8 or more carbon atoms, a phosphate ester having an alkyl group having 8 or more carbon atoms, or a fatty acid having an alkyl group having 8 or more carbon atoms The method for producing a plurality of types of polishing compositions according to claim 1 as described above.   A method for polishing a substrate, comprising: producing a polishing composition by the method according to claim 1, and polishing the substrate with the polishing composition to adjust the dishing amount of the substrate for planarization. The polishing method according to claim 11 , wherein the metal film is copper or a copper-containing alloy. The polishing method according to claim 11 , wherein the barrier metal film is tantalum or a tantalum alloy. A method for manufacturing a substrate having a dishing amount in the range of 1 to 300 nm, comprising a step of polishing the substrate by the polishing method according to claim 11 .

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